Aircraft brakes require many unique design features in order to function under the patterns of use which they must undergo. The use patterns of aircraft brakes pose extraordinary design problems in that the brakes are required to withstand extreme loads for very short periods of time. Furthermore, these brief intense load periods are separated by extended periods of time in which the brakes are not used at all. This unusual duty cycle for aircraft brakes therefore requires unique design features.
It is common practice to utilize a carbon disk stack in an aircraft brake assembly. The carbon disk stack is formed of alternating stator and rotor disks. The stator disks are fixed or keyed to a torque tube in the aircraft brake assembly. The rotors, however, are keyed to rotate with the aircraft wheel. When the aircraft brakes are applied, pistons located in a piston housing in the brake assembly compress the carbon disk stack so as to stop the rotation of the rotor elements, which in turn, stop the rotation of the aircraft wheels.
Aircraft brake designers have discovered that the most effective material from which to construct the stator and rotor disks is a carbon material. The stator and rotor disks used in the brake assembly require a high temperature resistant material which is capable of withstanding temperatures over 1,000.degree. Fahrenheit. Carbon, a high temperature resistant material, has proved to be most effective for use in the disks of the brake assemblies, and is widely used despite its high cost.
The use of carbon material in the disks, however, has created other problems in that carbon is a somewhat brittle material, which may be damaged by impact or shock. Therefore, when the brake assemblies are manufactured, shipped, installed, repaired or serviced, great care must be taken to avoid any damaging impact to the carbon disks. The additional labor and time required to prevent impact to the disks results in increased labor costs for manufacturing and shipping and added downtime in the installation and servicing of the brakes. This problem is exacerbated by the fact that the carbon disks are very expensive to replace. For example, each stack of carbon disks may cost up to $20,000 to $30,000. In the past, airlines have used wooden crates to protect the aircraft brake assemblies during shipping.
A lightweight aircraft brake assembly container is disclosed in W. A. Thomas, U.S. Pat. No. 4,790,430. This container is especially adopted for shipping certain portions of the brake assembly, primarily, the carbon disk portion. The container completely encloses the carbon disk stack with a body tube member, a base member, and a top closure member. Following initial assembly of the carbon disk stack and in the course of packaging the assembly for shipment, removal from the container before installation into the brake assembly on the aircraft, and during storage and installation after shipping, there is a significant danger that the carbon brake stack will be damaged by shock or impact.
Therefore, a need exists for a lightweight, impact-resistant device which will protect the carbon disks from damage during shipping of a carbon disk stack from the place of manufacture to the place of installation. A need also exists for a lightweight, impact-resistant device which will protect the carbon disks during shipping when the disk stack is fixed to a torque tube in the brake assembly.
Accordingly, the principal object of the present invention is to protect aircraft brake carbon disk stacks during shipping.
Another object of the present invention is to provide a device for protecting aircraft brake carbon disk stacks during shipping when the disk stack is fixed to a torque tube in the brake assembly.
A still further object of the present invention is to provide a device for protecting aircraft brake carbon disk stacks which is flexible and therefore easily installed by sliding the device over the carbon disk stack.
Another object of the present invention is to provide a device for protecting carbon disk stacks which is lightweight and impact-resistant.